(A) Field of the Invention
The present invention relates to a probing apparatus for semiconductor devices, and more particularly, to a probing apparatus equipped with a multiaxial manipulator for testing semiconductor devices such as the integrated circuit devices.
(B) Description of the Related Art
In the manufacturing process of integrated circuit devices, a probe card is used to probe electrical properties to select and discard integrated circuit devices that do not meet the product specifications. Traditionally, the probe card is designed according to the specification and the position of signal pads of the device under test, each probe is positioned on a supporter, and epoxy resin is used to adhere the probe onto the supporter. The probe card is then positioned on a printed circuit board conforming to the device under test. Finally, the position of each probe is precisely adjusted to meet the specification of the device under test in order to carry out accurate and steady electrical testing.
To reduce the test cost, current probe cards are being equipped with increasing numbers of probes to contact multiple integrated circuit devices so that testing can be performed on several devices at the same time. In such an arrangement, it is necessary to planarize the tips of the probes so that all of the probes contact the lead pads of the integrated circuit devices at substantially the same time and same pressure. If planarization is not achieved, some probes establish electrical connections with corresponding lead pads while other probes fail to establish electrical connections, thereby preventing accurate testing of the integrated circuit device. In particular, the lead pads to which excessive pressure is applied may be physically damaged, making it impossible to use the integrated circuit device in a finished product.
U.S. Pat. No. 5,861,759 shows an automatic probe card planarization system to planarize a first plane defined by a plurality of probes relative to a second plane defined by a top surface of a semiconductor wafer. A camera is used to measure the height of at least three selected probes relative to the plane of the wafer. Based on the measured values, the position of the first plane relative to the second plane is adjusted accordingly.
U.S. Pat. No. 5,974,662 shows a method for planarizing probes. The probes are mounted directly on a space transformer. This configuration is such that the orientation of the space transformer, and thus the orientation of the probes, can be adjusted without changing the orientation of the probe card. In this method, an electrically conductive metal plate, instead of the target semiconductor wafer, is provided as a reference plane. A cable and a computer are also provided in such a way that a computer display shows whether a conductive path is created for each probe relative to the metal plate.